Scientists at deCODE genetics have completed the largest study of ancient DNA from a single population ever undertaken. Analyzing mitochondrial DNA, which is passed from mother to offspring, from 68 skeletal remains, the study provides a detailed look at how a contemporary population differs from that of its ancestors.
The results confirm previous deCODE work that used genetics to test the history of Iceland as recorded in the sagas. These studies demonstrated that the country seems to have been settled by men from Scandinavia – the vikings – but that the majority of the original female inhabitants were from the coastal regions of Scotland and Ireland, areas that regularly suffered raids by vikings in the years around the settlement of Iceland 1100 years ago.
The current study further shows that the gene pool of contemporary Icelanders appears to have evolved rapidly over the intervening thousand years. As a result, the original female settlers are genetically less closely related to present-day Icelanders, and instead more closely related to the present day populations of Scotland, Ireland and Scandinavia, as well as those of northwestern and southwestern Europe.
A schematic representation of Iceland's population history. The circles represent the gene pools of the Scottish and Irish, Icelandic and Scandinavian population groups at different points in time. Circle diameter broadly reflects the relative population sizes. The vertical arrows represent the transmission of DNA between generations within populations, while the diagonal arrows represent the settlement of Iceland from 870 to 930 AD from Scotland, Ireland and Scandinavia.
This is a demonstration of a phenomenon known as 'genetic drift.' In essence, in any population certain individuals will have more offspring and, by chance and in this case over the course of 35 generations, many more descendants than others. And as a result, particularly in a small population, the genetic variety of the original population can decrease and change over time. In this study only mitochondrial DNA was studied, but the same phenomenon applies to the Y chromosome, which is passed from fathers to sons, and to any other part of the genome.
"This study is a major contribution to the use of ancient DNA studies in tracing the history not just of single populations, but of our species and how we spread from Africa to every corner of the globe," said Kari Stefansson, CEO of deCODE. "It is the first such study to be large enough to permit meaningful statistical methods to be applied to ancient DNA. We very much hope this will aid and encourage others to follow with large studies in other parts of the world."
CITATION: Helgason A, Lalueza-Fox C, Ghosh S, Sigurðardóttir S, Sampietro ML, et al. (2009) Sequences from First Settlers Reveal Rapid Evolution in Icelandic mtDNA Pool. PLoS Genet 5(1): e1000343. doi:10.1371/journal.pgen.1000343
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Sexual Fantasies: Threesomes Are Normal, Golden Showers Not So Much
- Ghost Light From Dead Galaxies - A Hubble Halloween
- US Wildlife Bans On GMOs And Neonics Lack Transparency And Scientific Rationale
- Is It Possible To Build A Spacesuit Or Spaceship To Travel Through The Sun With Future Tech? - Just For Fun.
- Does Max Tegmark Kill A Daughter In A Parallel World ?
- The Way Architecture Imitates Life, Biology Meets Geometry
- Greenpeace Says Its GMOs Are Better Than Science's GMOs, Still Hates Golden Rice
- "Verduyn is right on the money when he says it's not the emotion of sadness itself that's inherently..."
- "A very astute observation, given that they're both, in essence, electrical phenomena...."
- "A growing population is a huge problem because we take for granted the innovations that have..."
- " Well, perhaps, my inference and reply is faulty, but you do say Tolle basically claims his way..."
- "I'm flattered you think I wrote this. Jon will be less pleased...."
- Two-faced anti-GMO groups: Block crop and food innovations then claim Big Ag prevents GMO innovations
- Why support erodes for GMO labeling (Hint: It’s not because of spending by Big Ag)
- Genetic “hall of mirrors” with large palindromes, yet smaller: What’s mighty about the mouse
- Gut bacteria an easy scapegoat for disease, but connections hard to prove
- Vermont Rube Goldberg-like GMO labeling law exempts GMO filled natural supplements
- Downside to GMOs: Yields have become so good, they exceed processing capacity
- Fun and games make for better learners
- Avivagen publishes evidence for natural alternative to antibiotic use in livestock
- Drug tests on mothers' hair links recreational drug use to birth defects
- Bladderwrack: Tougher than suspected
- Scientists seek cure for devastating witches' broom disease of the chocolate tree